Adherent grease and method for manufacturing the same



Patented May 30. 1939 UNITED 'ISTA-TES 2,160,162 -ADHERENT GREASE ANDMETHOD FOR MANUFACTURING THE SAME Arnold J. Moi-way, Roselle, and JohnC. Zimmer,

Hillside,

N.'J., assignors to Standard Oil De-' velopment Company, a corporationof Delaware.

No Drawing. Application Mann, 1935,

Serial No. 11,002

9 Claims.

Thepresent invention relates to an improved grease compositionwhichischaracterized by strong adherent properties. The composition and itsmethod of manufacture will be fully understood from the followingdescription. I Y

Adherent greases have been known to the prior art but thosenow'available are not entirely satisfactory. This particular type ofgrease is char-- acterized by the property of adhering so strongly m tometal parts that thegrease is caused to permanently string out withoutseparating from the metal parts. -These greases are to be clearly'distinguished from the buttery or elastic type greases which tend toseparate rapidly from the metal parts and ball up rather thanpermanently string out. The adherent greases do not tend to spatterunder sudden shock as do the buttery type greases and for' this reasonthe former are more desirable where there is a likelihood of suddenshock or centrifugal force which tends to pull the grease away from themetal parts to be lubricated.

The former or known adherent greases have been usually prepared fromlubricating oils and aluminum stearate or similar. aluminum soaps, andrubber has beenadded, sometimes in the form of latex. These materialsare added to the oil, which is heated to incorporate the soap and driveoff any water and to form the grease. Such a. grease is useful buthascertain undesirable properties; for example, it tends to lose itsstructure if water is present and very stable emulsions are formed whichare, of course, highly objectionable. Also, this type grease tends topull out and leak excessively from'the bearing. These difficulties withthe characteristic of the aluminum soap used in their composition anditis highly desirable to produce an adherent grease which will not havethese objectionable features.

It is proposed herein to prepare an lime soap grease by the addition ofrubber in the form of latex or otherwise in order to obtain theadvantages of the lime soaps which make a grease more stable towardworking and more resistant to the action of water and showing less lossby leakage than the aluminum soap compounds referred to above. It hasbeen found, however, that the ordinary method of manufacturing thealuminum soap greases, in-which the oil soap and latex are mixedtogether and gently heated toremove the bulk of the moisture, is notapplicable to lime soap greases containing rubber. Lime soap productsproduced in that way are entirely unsatisfactory because they are heavyfluid 5 compounds devoid of all grease structure. The

' lar source, such as the paraffinic, mixed or naphpresent known greaseare adherent 3 or 4 to say 30% maybe used as wide limits and reason forthe difference in the behavior-of lime and aluminum soap compounds isunknown and the pre'sentapplicants content themselves with noting thisdifference and disclosing a' suitable method of manufacturing anadherent lime soap grease containing rubber.

In the manufacture of the lime 'soap grease it has been found to beimportant to add the rubber to a formed lime soap'grease, that is tosay, to add the rubberto a primary lime soap mixture 10 which has afirm' grease structure. If the rubber is added say'to the oil or soapbefore the 4 grease structure is obtained,- it has been found that heavyfluid mixtures are produced which do not possess a grease structure. Inthis respect 15. the lime soap compounds differ from those containingaluminum soaps.

The oil used in the present invention isa lubricating oil and may beselected from any particuthenic base crudes, and may be of any type,such 20 as the distillate or residual oils, and viscosity ranges of sayfrom to 2000 seconds Saybolt at F. may be selected- However, it ispossible 30 from vegetable oils suchas cottonseed or cocoanut oils andthe like; or from fish oils or the fat or soap acids of commerce suchas'oleic or stearic or their admixtures, or from synthetic acidsobtained by the oxidation of heavy oils and waxes 35 at lowtemperatures. The amount of the soap in the final composition depends tosome extent upon theparticular soap used and on the quality of thegrease desired butin most instances from ordinarily from 5 to 15% iscommercially most desirable.

Rubber is preferably added to the grease in the form of latex, a naturalmilky emulsion of rubber as it is obtained from the rubber 'tree,-butrubber 45 solutions in benzol may be used or other artificialdispersions. The amount of rubber in the finished grease should notbe'over about 5% by weight in any case, and may be as low as .1% in someinstances.

Other materials may be added=to the composition, such as anti-oxidantsto prevent the deterioration of'the rubber, for example .001 to .1% ofaldol alpha nap-hthylamine, or similar known aromatic amines or hydroxycompounds. Fillers.

such as chalk or graphite may be added, or Wax, petrolatum, lubricatingoil dyes, glycerine, glycols, or the higher alcohols, to produceparticular qualities desired for specific purposes. A small amount ofwater is almost always present as inall lime greases, say from A; to 5%of the whole, in order to produce a smooth, uniform soap dis- 7 persionfree from lumps.

In the manufacture of the grease a major proportion of the oil is placedin a kettle and the fat or fat acid added thereto. This mixture isheated and lime, preferably hydrated lime, added with constant heatingand agitation so as to effect the saponification and dehydration.Materials other than'the rubber may be added at this point if desiredand the mass is cooled say to about 200 F., at which point water may beadded so as to have present the requisite amount and the soap dispersionformed. The mixture is then further cooled to say F. or below, producinga firm grease structure. This product will be referred to herein as theprimary grease.

The latex is added to a .minor fraction of the oil and this is gentlyheated so as to drive of! the water present in the latex, leaving therubber particles dispersed throughout the oil. The amount of oil usedfor this purpose should be calculated so as to produce a dispersioncontaining not more than say 1 to 5 or 10% of rubber, as this is aboutas heavy as can be conveniently handled. This mass is completelydehydrated, preferably under vacuum or by blowing withair, and is thenthoroughly stirred or worked into the primary grease at a temperature ofsay 100 or F. until uniformity is attained.

As a specific example of the present grease mixture and its method ofpreparation, the following examples may be given:

Example I An ordinary lime soap grease was prepared having the followingcomposition:

Percent Lime soap 12 Solar Red oil 86 Glycerine 1 Water 1 This greasewas soft and buttery and had an A. S. T. M. penetration of 325 at 77 F.The grease was not adherent.

Example II A lime soap compound was prepared or the followingcomposition, using the same fatty materials and the same oil as in theprevious example; but including rubber. The material was made by puttingthe fat, oil, lime'and latex into a kettle and heating to 350 F., thenagitating to remove the bulk of the water which was adjusted to 1%:

Percent Lime soap 12.0 Rubber 0.5 Glycerine 1.0 Water 1 1.0 Solar Red011 85.5

An adherent grease was then prepared according to the present method,having an ap- Percent Lime soap 12.0 Glycerine 1.0 Rubber .5

'Water .75 Oil 85.75

This grease had an excellent structure, showed a penetration of 367 at77 F., and was firm with stringy, adherent properties.

Example I V The following comparative tests show the advantages of limesoap greases containing rubber over the ordinary buttery lime greases orthe aluminum soap greases containing rubber. The samples are as follows:

#1--a lime soap grease containing about 2% of the soap with no rubber.#2--an aluminum soap grease containing 0.5%

rubber. #3a grease similar to #1 to which has been added 0.5% rubber andmade according to the present invention.

A. S. T. M. penetration (sec) @77 F. @30 F. @O F.

It will be observed that #2 became excessively hard at 0 F. while #3showed the least change.

The average delivery pressure required for greasing pin and bushingshackles with a Bal- Crank gun were observed with the three samples at 0F.

#/sq. in. #1 1350 #2 -5. 2200 The pressure required in the case of #2 istwice that required for #3, indicating the much greater ease ofservicing.

A well worn Chevrolet 1931 model was put under test with the threegreases and the mileage at which squeaks were noticed was determinedafter each servicing.

Mileage when chassis squeaks were first noted Miles #1 250 #2 800 #31200 The present invention is not limited to any theory of the greasefor adherent properties nor to the particular composition given in theillustrative examples, nor to any particular method of manufacturing thegrease, but only to the fol lowing claims in which it is desired toclaim all novelty inherent in the invention.

We claim: 1. Method for preparing an adherent lime soap greasecomposition comprising thoroughly incorporating a lime soap into alubricating oil while mixture to form a rubber-tree priheating the maryproduct having a substantially stable grease structure, forming adispersion oi rubber in an additional quantity of said lubricating oil,cooling the primary product, and incorporating said dispersion of rubberin oil with said product at substantially the temperature thereof.

2. A method for preparing an adherent and coherent lubricatingcomposition comprising, thoroughly incorporating a lime soap into alubricating oil,-while heating the mixture. cooling the mixture toobtain a primary product having a substantially stable grease structureand working into said product a small rubber dispersed in a solventthereior.

8. Method according to claim 2 in which the water contentoi the primarymixture of the lime soap and the oil is adjusted to an amount less than5%, and

s rubber is dispersed ina amount or I -9. A method according product.the mass is cooled to obtain a smooth grease structure before theaddition or the rubber dispersion. I l

4. Method according to claim 2 in which the rubber dispersion in oilcontains less than about 5% of rubber.

5. A method according to cl'aim2 in which the mixture of lime soap andlubricating oil is prepared at a temperature about 200 F. and thedispersion of rubber in solvent worked into the primary-product aftercooling to a temperature between and F.

6. A method according to claim 2 in which the ingredient rubber isuncoagulated rubber from latex.

7. A method according to claim 2 in which the hydrocarbon solventtherefor.

8. A method according rubber is dispersed in a lubricating oil as asolvent therei'or.

to claim 2 in' which the dispersion 0! rubber is dehydrated toasubstantial degree prior to its incorporation in the primary mom J.MonwAY. com: 2. am.

to claim 2 in which the

